400 unknown message type - on verify pin

[nks017]

Question

I have connect to the socket now I want to authenticate with a PIN I have received the PIN after that I tried to verify but 400 error.

let verificationRequest: [String: Any] = [
            "type": "request",
            "id": "verify_0",
            "payload": [
                "pin": 1212121
            ]
        ]
        
   if let jsonData = try? JSONSerialization.data(withJSONObject: verificationRequest, options: []),
        let jsonString = String(data: jsonData, encoding: .utf8) {
        socket?.write(string: jsonString)
   }

{"type":"error","id":"verify_0","error":"400 unknown message type","payload":{}}